At least 21 people have died and more are feared missing after the roof of a supermarket in the Latvian capital Riga collapsed.

Rescue efforts continued through the night and police have launched a criminal investigation.

Three of those killed were emergency workers who were helping people trapped when more of the roof came down.

A view from a nearby building shows the extent of the collapse

The cause of the collapse is unclear although reports say a garden was being constructed on the roof at the time.

The supermarket, which opened in 2011, is part of the Maxima retail chain.

(Source: BBC)